JP2004348800A - Information reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate a highly accurate drop-out detection signal. <P>SOLUTION: An information reproducing device is equipped with a pickup 15 for reading information from a recording track, a wobble signal detection means 16 for detecting a wobble signal from the read information,an A/D conversion means 17 for converting the detected wobble signal into a digital signal, a frequency analysis means 21 for analyzing the frequency of the digitalized wobble signal and a scratch prediction means 22 for outputting a scratch discrimination signal by discriminating a scrach on a disk 13 based on the frequency analysis result. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical disk recording / reproducing apparatus for reproducing information data modulated from a recordable optical disk represented by a CD-R or the like, and more particularly to a wobble (hereinafter referred to as wobble) signal from a meandering recording track on the optical disk. The present invention relates to an information reproducing apparatus that reproduces information.
[0002]
[Prior art]
Conventionally, recordable optical disks include a write-once type (Write Once) and a rewritable type (Erasable). On these recordable optical disks, the absolute address information on the disk, the optimum laser power for recording on the disk, and the like are bi-phase-modulated, and then this is FM-modulated to form a small wobble on the recording track in advance. Recorded on the disc. This is called ATIP (Absolute Time In Pregroove), and when a CD-R is reproduced at a normal linear velocity, the center frequency of the wobble is 22.05 [kHz].
[0003]
At the time of recording and reproduction, the CD-R disc detects the ATIP information by reproducing the wobble signal having the center frequency of 22.05 [kHz]. Particularly, at the time of recording, the ATIP information is used to confirm the recording position. There is no means other than the use of, and stable detection of ATIP information is indispensable in considering improvement in recording quality on a disc.
[0004]
FIG. 5 is a block diagram showing a main configuration example of a conventional optical disc reproducing apparatus. 5, reference numeral 1 denotes a recording optical disk, 2 denotes a spindle motor for rotating the optical disk 1, 3 denotes a motor rotation control circuit for controlling the rotation of the spindle motor 2, 4 denotes a laser pickup, and 5 denotes a wobble signal detection circuit. , 6 denotes a band-pass filter (BPF) for extracting only a predetermined frequency component from the detected wobble signal, 7 denotes a wobble binarization circuit for binarizing the wobble signal, and 8 denotes an ATIP address information detection circuit. , 9 are ATIP address data and 10 is a dropout signal.
[0005]
Hereinafter, the operation of the information reproducing apparatus according to the related art having the above configuration will be described. The motor rotation control circuit 3 generates a signal (not shown) corresponding to the rotation speed of the spindle motor 2 based on a pulse signal (not shown) generated according to the rotation of the spindle motor 2, and outputs the signal to a predetermined target. A spindle motor control signal is obtained by generating a rotation error signal (not shown) in comparison with the value and performing a filtering process or the like on this signal. By this control signal, the spindle motor 2 can be driven at a predetermined speed.
[0006]
As a driving method of the spindle motor, a Sync (synchronization) signal included in the ATIP information generated by the ATIP address information detection circuit 8 is used so that the Sync signal is detected at a predetermined target time. A circuit for controlling the rotation speed of the spindle motor 2 is also generally widely known.
[0007]
Further, a focus error signal and a tracking error signal output from the laser pickup 4 are input, a phase compensation and the like are performed on these signals by a servo circuit (not shown), and an actuator of the laser pickup 4 is operated based on the output signal. By driving (not shown), control is performed to move the objective lens so that the light beam spot follows the recording surface of the recording optical disc 1 and also follow the recording track.
[0008]
The signal detected by the laser pickup 4 is input to a wobble signal detection circuit 5, and the wobble signal detection circuit 5 detects a wobble signal of the recording optical disc 1 from the input detection signal. FIG. 6 is a view for explaining the movement of the laser pickup 4 at this time.
[0009]
In FIG. 6, reference numeral 11 denotes a laser beam spot focused on the recording surface, and reference numeral 12 denotes a wobble generated on the recording optical disk 1. The arrow indicates the direction in which the laser beam spot 11 relatively moves on the recording surface as the recording optical disc 1 rotates. When the tracking control is normally performed, the laser beam spot 11 accurately traces the target track on the recording optical disc 1 and proceeds in the direction of the arrow.
[0010]
The tracking frequency of normal tracking is sufficiently slower than the wobble center frequency (22.05 [kHz]), so that tracking control hardly follows the wobble signal. Therefore, the wobble signal can be interpreted as a tracking error component. The circuit for detecting the tracking error component will not be described here.
[0011]
The BPF 6 is used as a circuit for extracting only the wobble signal from the tracking error signals detected in this way. The center pass frequency of the BPF 6 is 22.05 [kHz] at 1 × speed reproduction. This is nothing but the center frequency of the wobble signal. The output signal of the BPF 6 is input to a wobble binarization circuit 7 for bi-phase demodulation.
[0012]
The quality of the binarized data output from the wobble binarization circuit 7 has a great influence on the quality of the ATIP address information or the quality of the spindle motor control during the recording operation. Therefore, various techniques have been devised to improve the quality of the binary data. As one method, it is known to improve the S / N ratio of the center frequency band of the wobble signal to improve the accuracy of the binary data (see Patent Document 1).
[0013]
The binarized data output from the wobble binarization circuit 7 is input to the ATIP address information detection circuit 8. The ATIP address information detection circuit 8 performs bi-phase demodulation and FM demodulation processing to generate address data 9. The ATIP address information detection circuit 8 can generate the dropout signal 10 by utilizing the characteristic that the wobble binary data has a center frequency of 22.05 [kHz] (at the time of 1 × speed reproduction).
[0014]
The dropout signal 10 is a signal indicating that the wobble signal from the recording optical disc 1 was not normally reproduced. The dropout signal 10 plays a very important role when recording on the recording optical disc 1. The reason that the dropout signal 10 is detected indicates that the wobble signal on the optical disc 1 cannot be normally reproduced, and the PLL for recording clock generation comes out of the locked state due to the influence of the dropout signal 10 and runs away. Because there is fear.
[0015]
[Patent Document 1]
JP-A-2002-63766 (page 3, FIG. 1)
[0016]
[Problems to be solved by the invention]
Therefore, the dropout detection signal is applied to a hold signal of a recording PLL or the like. However, since the dropout detection signal 10 is generated after the wobble signal is binarized, there is a problem in detection accuracy, which causes deterioration in the quality of a recording clock and the like, and eventually causes deterioration in the recording accuracy. I was
[0017]
The present invention has been made in view of the above circumstances, and has as its object to provide an information reproducing apparatus that can generate a highly accurate dropout detection signal.
[0018]
[Means for Solving the Problems]
2. The information reproducing apparatus according to claim 1, wherein said information reproducing apparatus reproduces a wobble signal from a disk having a meandering recording track, wherein said reading means reads information from said recording track, and said wobble detects a wobble signal from said read information. Signal detection means, A / D conversion means for converting the detected wobble signal into a digital signal, frequency analysis means for performing a frequency analysis of the digitized wobble signal, and the disk based on the frequency analysis result Flaw predicting means for determining a flaw above and outputting a flaw determination signal.
[0019]
According to the above configuration, since the flaw determination signal for determining the presence or absence of a flaw on the disk is generated based on the frequency analysis result of the wobble signal, the dropout detection signal is generated using the generated flaw determination signal. Thus, a highly accurate dropout detection signal can be generated.
[0020]
The information reproducing apparatus according to claim 2 is the information reproducing apparatus according to claim 1, wherein the flaw prediction means predicts a periodic flaw from a frequency distribution obtained by frequency analysis of the wobble signal, and reproduces the flaw position before reproducing the flaw position. The flaw prediction signal is output.
[0021]
According to the above configuration, by outputting the flaw prediction signal before reproducing the flaw position, if the flaw prediction signal is detected and the PLL circuit for recording clock generation is held, runaway of the PLL circuit can occur. Can be avoided.
[0022]
According to a third aspect of the present invention, in the information reproducing apparatus according to the first or second aspect, the information reproducing apparatus further includes an amplitude correction unit that performs an amplitude correction of the wobble signal using the flaw determination signal as an enable signal.
[0023]
According to the above configuration, during the period in which the flaw determination signal is input, the amplitude of the wobble signal can be restored to the same level as that of the normal wobble signal, the loss of the wobble signal can be eliminated, and the stable wobble signal can be reproduced. Can be.
[0024]
5. The information reproducing apparatus according to claim 4, wherein said information reproducing apparatus reproduces a wobble signal from a disk having a meandering recording track, wherein said reading means reads information from said recording track, and said wobble detects a wobble signal from said read information. Signal detection means, A / D conversion means for converting the detected wobble signal into a digital signal, frequency analysis means for performing frequency analysis of the digitized wobble signal, and the disk based on the frequency analysis result Motor control means for controlling the rotation of the motor for rotating the motor.
[0025]
According to the above configuration, by controlling the rotation of the motor based on the frequency analysis result of the wobble signal, the disk can be controlled at a constant linear velocity.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram showing an information reproducing apparatus according to the first embodiment of the present invention. In FIG. 1, 13 is a recording optical disk having meandering recording tracks, 14 is a spindle motor for rotating the optical disk 13, 15 is a laser pickup for reading information from the recording tracks, and 16 is a wobble signal detecting means for detecting a wobble signal. , 17 are A / D conversion means for converting a wobble signal into a digital signal, 18 is a band pass filter (BPF) for extracting only a predetermined frequency component from the detected wobble signal, 19 is a wobble binarization means, Reference numeral 20 denotes an ATIP decoder, 21 denotes frequency analysis means for performing frequency analysis of the wobble signal converted into a discrete digital value, and 22 denotes a flaw prediction for predicting flaws on the optical disk 13 based on the analysis result output from the frequency analysis means 21. Means, 23 is ATIP address data, 24 is a dropout signal, 5 is a flaw determination signal output from the wound predicting means 22.
[0027]
In FIG. 1, the optical disk 13 is rotated by being driven by a spindle motor 14, a laser pickup 15 traces the rotating optical disk 13, and a signal detected by the laser pickup 15 is input to a wobble signal detection unit 16. The wobble signal detection means 16 detects a wobble signal from the input detection signal of the laser pickup 15 and outputs it to the A / D conversion means 17. A / D converter 17 converts the wobble signal into discrete digital data. Although the sampling frequency and the number of output bits of the A / D converter 17 are not mentioned here, considering that the wobble signal is 22.05 ± 1 [kHz], 48 [kHz] at the time of 1 × speed reproduction. It is desirable that the above sampling frequency be used.
[0028]
The wobble signal converted into the discrete digital value is input to the BPF 18 whose band is limited at a center frequency of 22.05 [kHz], and noise components other than the signal necessary for ATIP decoding are removed here. This signal is input to the binarizing means 19 and decoded by the ATIP decoder 20. The ATIP decoder 20 outputs ATIP address data 23 and a dropout signal 24.
[0029]
The wobble signal converted into a discrete digital value by the A / D converter 17 is input to the frequency analyzer 21. One example of the frequency analysis means is FFT (Fast Fourier Transform) processing.
[0030]
Here, a case where a scratch having a diameter of 1 [mm] is present on the optical disc 13 is considered. In the case of CDs, the track pitch is specified by 1.6 [μm] in the standard, so that the scratches having a diameter of 1 [mm] extend over 625 tracks. In the case of 1 × speed reproduction, the reproduction time is (25 × 2 × π × 625) /1.2×103=82 [s] at the innermost circumference of the disc, and at the outermost circumference of the disc, (50 × 2 × π × 625) /1.2×103=163 [s].
[0031]
When a scratch is present at a certain position on the optical disc 13, the wobble signal obtained by reproducing the optical disc 13 has a certain frequency characteristic. If there is one flaw having a diameter of 1 [mm] as in the previous example, the innermost circumference is 1.2 × 103 / (25 × 2 × π) = 7.6 [Hz] at 1 × speed, In the case of the outermost circumference, a peak of 1.2 × 103 / (50 × 2 × π) = 3.8 [Hz] stands.
[0032]
When there are a plurality of scratches on the optical disc 13 and the laser pickup 15 traces over the plurality of scratches while the optical disc 13 rotates once, the frequency component is multiplied by the number of traced scratches. The frequency component of the value is observed. Even in such a case, the center frequency of the wobble signal is sufficiently away from 22.05 [kHz], and the low-frequency component of the frequency analysis result can be considered to be a response due to a flaw.
[0033]
The flaw prediction means 22 focuses mainly on the peak in the low frequency range from the output result of the frequency analysis means 21. If a peak equal to or greater than a certain threshold is found in the low frequency range, it is recognized that there is a flaw on the disk 1 and a flaw determination signal 25 is output.
[0034]
Further, by performing frequency analysis of the wobble signal, it is possible to predict a periodic flaw on the optical disc 13 and output the flaw prediction signal 25 immediately before reproducing the flaw position.
[0035]
As described in the previous example, when a scratch having a diameter of 1 [mm] is formed on the disk, the scratch exists over 625 tracks. In other words, the scratch position is traced almost every 625 times. When a flaw is present at the outermost circumference, a spectrum of 3.8 [Hz] is obtained according to the above calculation. This is because the flaw position is traced every 1 / 3.8 = 0.26 [s]. Is equivalent to doing
[0036]
In other words, after detecting a flaw at a certain position, it is predicted that the flaw position will be reproduced after 0.26 [s]. As described above, the frequency distribution of the flaw is calculated from the result of the frequency analysis of the wobble signal, the periodic flaw is predicted from the result, and the flaw prediction signal 25 can be output immediately before the flaw position is reproduced.
[0037]
According to the present embodiment, it is possible to determine the presence or absence of a scratch on the optical disc 13 by performing the frequency analysis of the wobble signal. By combining the flaw discrimination signal 25 and the dropout signal 24, a more accurate dropout signal can be generated.
[0038]
By the way, a clock signal generator of an optical disk recording device reproduces a wobble signal from a wobble of a track on a disk and generates a recording clock signal synchronized with the wobble signal. Data is recorded at a desired position on the optical disk based on the recording clock signal. At this time, by using a highly accurate dropout signal as a hold (HOLD) signal of the recording clock generation PLL circuit, it is possible to reliably prevent the recording clock generation PLL circuit from coming out of the locked state. In addition, a stable and highly accurate recording operation can be realized, and the recording quality can be improved.
[0039]
FIG. 2 is a block diagram showing an information reproducing apparatus according to the second embodiment of the present invention. In FIG. 2, 26 is a recording optical disk having meandering recording tracks, 27 is a spindle motor for rotating the recording optical disk 26, 28 is a laser pickup for reading information from the recording tracks, 29 is a wobble signal for detecting a wobble signal Detecting means, 30 is A / D converting means for converting the detected wobble signal into a digital signal, 31 is frequency analyzing means for analyzing a frequency component of the wobble signal converted into a discrete digital value, and 32 is output from the frequency analyzing means. Flaw prediction means for predicting flaws on the optical disk 26 based on the analysis result; 33, amplitude correction means for correcting the amplitude of the output digital value of the A / D conversion means 30; 34, a predetermined frequency from the detected wobble signal BPF for extracting only components, 35 is a wobble binarizing means, 36 is an ATIP decoder 37 ATIP address data, 38 is a drop-out signal outputted from the wound predicting means 32.
[0040]
Here, the size of a wobble signal loss when a scratch having a diameter of 1 [mm] is formed on a recordable optical disk will be considered. Assuming that the linear velocity of the CD is 1.2 [m / s], a flaw having a diameter of 1 [mm] results in data loss of 1/1200 [s]. This means that when the wobble frequency is 22.05 [kHz], wobble data of 22.05 × 103/1200 = 18.375 cycles is lost, and the quality of the ATIP address data of the ATIP decoder 36 is greatly deteriorated. become. Such a loss of the wobble signal can be avoided by the present embodiment.
[0041]
Next, the operation of the present embodiment will be described. The laser pickup 28 traces the optical disk 26 which is driven by the spindle motor 27 and rotates, and the detection signal is input to the wobble signal detection means 29.
[0042]
The wobble signal detection means 29 detects a wobble signal from the detection signal of the laser pickup 28, and this wobble signal is converted into discrete digital data by the A / D conversion means 30. It is desirable that the sampling frequency of the A / D conversion means 30 be a sampling frequency of 48 [kHz] or more at the time of 1 × speed reproduction as in the first embodiment. The wobble signal converted into a discrete digital value by the A / D converter 30 is input to the frequency analyzer 31. One example of the frequency analysis unit 31 is an FFT (Fast Fourier Transform) process.
[0043]
If there is a flaw at a certain position on the optical disk 26, the wobble data obtained by reproducing the disk has a certain frequency characteristic. In the case where there is one, a peak of 7.6 [Hz] at 1 × speed occurs at the innermost circumference and 3.8 [Hz] at the outermost circumference at the 1st speed. When there are a plurality of scratches on the optical disc 26 and the laser pickup 28 traces over the plurality of scratches while the optical disc 26 makes one rotation, the frequency component is multiplied by the number of traced scratches. The frequency component of the value is observed. Even in such a case, the wobble signal is sufficiently separated from the center collection frequency 22.05 [kHz], and the low-frequency component of the frequency analysis result can be considered to be a response due to a flaw.
[0044]
The flaw predicting means 32 focuses mainly on the peak in the low frequency range from the output result of the frequency analyzing means 31. If a peak equal to or greater than a certain threshold is found in the low frequency range, it is recognized that there is a flaw on the optical disc 26, and a flaw determination signal 25 is output. The amplitude correction means 33 receives as input the flaw discrimination signal 25 output from the flaw prediction means 32 and the wobble signal converted into a discrete digital value output from the A / D conversion means 30. In this case, the flaw determination signal 25 is used as a correction enable signal of the amplitude correction means 33.
[0045]
The amplitude corrector 33 calculates an amplitude value of the wobble signal. The wobble signal differs from a normal analog audio signal or the like in that there is no large fluctuation in both frequency and amplitude. By utilizing the regularity of the wobble signal, for example, when the amplitude value is less than a certain amplitude, it is possible to consider that the signal is missing due to a flaw or the like, and to correct the amplitude value. The amplitude correction means 33 receiving the correction enable signal corrects the amplitude value only in that section.
[0046]
FIG. 3 is an example of a method of correcting an amplitude value in the amplitude correction means 33. Reference numeral 39 denotes sampling data of a correct wobble signal, reference numeral 40 denotes sampling data when the wobble signal is not correctly reproduced due to a flaw or the like, and reference numeral 41 denotes corrected sampling data obtained by correcting the sampling data 40.
[0047]
Here, the n-th sampling data is defined as Sn. At this time, an operation of Sn- (Sn-1) is performed. If the operation result is a positive value, the slope is positive; if the operation result is negative, the slope is negative. The point at which the operation result changes from positive to negative is the maximum positive amplitude value, and the point at which the operation changes from negative to positive. Is the point of maximum negative amplitude. The amplitude correction means 33 compares the maximum amplitude point obtained in this way with a predetermined threshold value of ΔAmax and ΔAmin, and corrects the data when the maximum amplitude value of the sampling data is less than the threshold value. Correction of the maximum amplitude value can be performed.
[0048]
That is, when the correct wobble signal sampling data 30 as shown in FIG. 3A is input, the amplitude correction means 33 does nothing and outputs this data to the BPF 34 as it is. However, when the sampling data 30 of the abnormal wobble signal as shown in FIG. 3B is input, the amplitude correcting means 33 corrects the sampling data and corrects the sampling data as shown in FIG. The sampling data 41 is output to the BPF.
[0049]
According to the present embodiment, as a result of the data correction by the amplitude correction means 33, even if the disk has a scratch, the loss of the wobble signal can be minimized and the stable wobble signal can be reproduced. Since the ATIP decoding described above can be realized, the recording quality can be improved by suppressing the quality deterioration of the ATIP address data 37. Further, the control quality of the spindle motor 27 can be improved.
[0050]
Further, since the wobble data is corrected by the amplitude correction means 33, it is difficult to fall into a dropout state, and ATIP decoding can be further stabilized.
[0051]
FIG. 4 is a block diagram of an information reproducing apparatus according to the third embodiment of the present invention. In FIG. 4, reference numeral 42 denotes a recording optical disk, 43 denotes a laser pickup, 44 denotes a wobble signal detecting unit, 45 denotes an A / D converting unit for converting the detected wobble signal into digital data, and 46 denotes a converted digital value. Frequency analysis means 47 for analyzing the frequency component of the wobble signal, motor control means 47 for driving a spindle motor 48, and 48 a spindle motor for rotating the recording optical disc 42.
[0052]
The laser pickup 43 traces the optical disk 42 which is driven by the spindle motor 48 and rotates, and its output signal is input to the wobble signal detecting means 44. The wobble signal detecting means 44 generates a wobble signal from the detection signal of the laser pickup 43. The detected wobble signal is input to the A / D converter 45 and is converted into discrete digital data.
[0053]
Here, it is desirable that the sampling frequency and the number of output bits of the A / D conversion means 45 be 48 [kHz] or more at the time of 1 × speed reproduction as in the first embodiment.
[0054]
The wobble signal converted into the discrete digital value by the A / D conversion means 45 is input to the frequency analysis means 46. One example of the frequency analysis means 46 is FFT (Fast Fourier Transform) processing. Looking at the output of the frequency analysis means 46, a peak of 22.05 [kHz] appears if the 1 × speed reproduction is normally performed due to the characteristics of the wobble signal. Conversely, if the peak stands at 22.05 [kHz], it can be said that the optical disc 42 is being reproduced at 1 × speed.
[0055]
Since the analysis information of the wobble signal of the frequency analysis means 46 is input to the motor control means 47, the motor control means 47 pays attention to the peak value of the analysis information, and if the peak value is lower than the target frequency, the spindle motor 48 When the acceleration signal is higher than the target frequency, a deceleration signal is given to the spindle motor 48 to control the spindle motor 48 to always rotate at the target value. Rotate.
[0056]
According to the present embodiment, the rotation of the spindle motor 48 is controlled so that the deviation from the center frequency of the wobble signal does not occur, and the rotation of the optical disk 42 can be controlled at a constant linear velocity.
[0057]
When performing n-times speed reproduction, a control signal for the spindle motor 48 may be generated such that the peak value becomes 22.05 × n [kHz].
[0058]
【The invention's effect】
According to the present invention, since the flaw determination signal for determining the presence / absence of a flaw on the disk is generated based on the frequency analysis result of the wobble signal, the dropout detection signal is generated using the generated flaw determination signal. Thus, a highly accurate dropout detection signal can be generated.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an information reproducing apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of an information reproducing apparatus according to a second embodiment of the present invention.
FIG. 3 is a view for explaining the operation of the amplitude correction means shown in FIG. 2;
FIG. 4 is a block diagram showing a configuration of an information reproducing apparatus according to a third embodiment of the present invention.
FIG. 5 is a block diagram showing a configuration of a conventional optical disc reproducing apparatus.
FIG. 6 is a diagram showing a trace state of a laser pickup with respect to a wobble on a disk.
[Explanation of symbols]
13, 26, 42 Recording optical discs 14, 27, 48 Spindle motors 15, 28, 43 Laser pickups 16, 29, 44 Wobble signal detection means 17, 30, 45 A / D conversion means 18, 34 BPF
19, 35 Wobble binarization means 20, 36 ATIP decoder 21, 31, 46 Frequency analysis means 22, 32 Flaw prediction means 33 Amplitude correction means 47 Motor control means

Claims (5)

In an information reproducing apparatus for reproducing a wobble signal from a disk having a meandering recording track,
Reading means for reading information from the recording track;
Wobble signal detection means for detecting a wobble signal from the read information,
A / D conversion means for converting the detected wobble signal into a digital signal;
Frequency analysis means for performing frequency analysis of the digitized wobble signal,
Flaw prediction means for determining a flaw on the disk based on the frequency analysis result and outputting a flaw determination signal;
An information reproducing apparatus comprising: 2. The information reproducing apparatus according to claim 1, wherein the flaw prediction means predicts a periodic flaw from a frequency distribution obtained by frequency analysis of the wobble signal, and outputs the flaw prediction signal before reproducing a flaw position. 3. The information reproducing apparatus according to claim 1, further comprising an amplitude correction unit configured to perform an amplitude correction of the wobble signal using the flaw determination signal as an enable signal. In an information reproducing apparatus for reproducing a wobble signal from a disk having a meandering recording track,
Reading means for reading information from the recording track;
Wobble signal detection means for detecting a wobble signal from the read information,
A / D conversion means for converting the detected wobble signal into a digital signal;
Frequency analysis means for performing frequency analysis of the digitized wobble signal,
Motor control means for performing rotation control of a motor that rotates the disk based on the frequency analysis result,
An information reproducing apparatus comprising: 4. A disk recording apparatus using a flaw determination signal obtained by the information reproducing apparatus according to claim 1 as a hold signal of a recording clock generation PLL circuit.

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